ISSUE ENVIRONMENT:
If you hold your Pandora in your hands, you only have your thumbs for typing, hence your typing abilities are quite limited.
It is hard to press more than 2 keys, and hard to press 2 keys on the same side, as your second thumb does not reach the opposite side all too easy (except you have a basketball player's hands).
The modifier keys Start/ALT Select/CTRL Pandora/(META, I guess?) are in the middle of the keyboard, hence the can easily pressed together with another key. But SHIFT lies at an ergonomically problematic side (left boundary). Hence hard to press with other left side keys.
SUGGESTED SOLUTION:
I suggest that Pandora OS offers an optional and configurable input help.
[1|2|3 presses | hold for duration x] SHIFT [timeout y] [modifier key 2] [timeout z] key
Produces the same result like SHIFT + modkey2 + key
Very likely modifier key 2 and timeout z are not necessary, as you can trigger the SHIFT hold (by your defined action), and then press the modifier key 2 and the other key at once, as the other modifier keys are laid at a central (ergonomically better) position.